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3 years ago

A newspaper and a metal lunchbox are sitting in sun. Why does metal lunchbox feel hotter to touch than a newspaper?

Physics

1 answer:

Thepotemich [5.8K]3 years ago

3 0

Answer:

Explanation:

the metal lunchbox has a higher conductivity

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A transformer supplies 60 watts of power to a device that is rated at 20 volts. The primary coil is connected to a 120-volt ac s

Nataly [62]

Answer:

I = 0.5 A

Explanation:

Given: P=60 Watts, Voltage supply V = 120 Volts (for primary coil)

Solution:

we have P = V I

⇒ I = P /V = 60 Watts / 120 Volts

I = 0.5 A

4 0

3 years ago

A 2.3 kg particle-like object moves in a plane with velocity components vx = 40 m/s and vy = 75 m/s as it passes through the poi

Sonbull [250]

Answer:

(a) $\overrightarrow{L}=885.5\widehat{k}$

(b) $\overrightarrow{L}=1046.5\widehat{k}$

Explanation:

mass, m = 2.3 kg

vx = 40 m/s

vy = 75 m/s

(a) Angular momentum is given by

$\overrightarrow{L}=\overrightarrow{r}\times \overrightarrow{p}$

Where, p is the linear momentum and r is the position vector about which the angular momentum is calculated.

Here, $\overrightarrow{r}=3\widehat{i}-4\widehat{j}$

$\overrightarrow{p}=m\overrightarrow{v}$

$\overrightarrow{p}=2.3\left ( 40\widehat{i}+75\widehat{j} \right )$

$\overrightarrow{p}= 92\widehat{i}+172.5\widehat{j}$

So, the angular momentum

$\overrightarrow{L}=\left ( 3\widehat{i}-4\widehat{j} \right )\times\left ( 92\widehat{i}+172.5\widehat{j} \right )$

$\overrightarrow{L}=885.5\widehat{k}$

(b) Here, $\overrightarrow{r}=(3+2)\widehat{i}+(-4+2)\widehat{j}$

$\overrightarrow{r}=5\widehat{i}-2\widehat{j}$

$\overrightarrow{L}=\left ( 5\widehat{i}-2\widehat{j} \right )\times\left ( 92\widehat{i}+172.5\widehat{j} \right )$

$\overrightarrow{L}=1046.5\widehat{k}$

6 0

3 years ago

What will the pressure of gas be if the temperature rises to 87°C

weeeeeb [17]

Answer: 0 degrees Celsius or 32 degrees Fahrehit

Explanation:

3 0

3 years ago

An archer pulls a bowstring back a distance of 20 cm with an average force of 75 N. The arrow has a mass of 20.0 g. When he rele

Masja [62]

To solve this problem we will apply the concepts related to the work theorem for which it is defined as the product of Force and distance. In turn, we will use the energy conservation theorem for which the applied work must be equivalent to the total kinetic energy on the body.

The work is defined as

$W = Fd$

Here,

F = Force

d = Displacement

Replacing with our values we have that

$W = 75*0.2$

$W = 15J$

Now by conservation of energy,

$W = KE$

$W = \frac{1}{2}mv^2$

$15 = \frac{1}{2} (20*10^{-3}kg)(v^2)$

Solving for v,

$v = 10\sqrt{15}$

$v = 38.72 \approx 39$

Therefore the correct answer is D.

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3 years ago

Explain ALL THREE of Newton’s Laws in your own words.

Svet_ta [14]

Explanation:

(1) Every object moves in a straight line unless acted upon by a force. (2) The acceleration of an object is directly proportional to the net force exerted and inversely proportional to the object's mass. (3) For every action, there is an equal and opposite reaction.

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3 years ago